Homemade explosives found on Maryland mall shooter

A police helicopter flies over the scene at the Mall in Columbia. (Source: @youvebeenhealthd/CNN)

People leave the mall as police check out the scene. (Source: CNN)

COLUMBIA, MD (RNN) - Police found what appeared to be explosive devices on the person they said shot and killed two employees of The Mall in Colombia on Saturday.

The Howard County Police Department said in a news release investigators searched the male suspect's bag and found "two crude devices" he made using fireworks. He was dead when police arrived on the scene, apparently from a self-inflicted gunshot wound.

He has been tentatively identified, but investigators are working to further confirm who he is before releasing his name. Police K-9 units were still searching the mall late Saturday night as a precaution.

Brianna Benlolo, 21, and Tyler Johnson, 25, were found dead inside a skateboard store called Zumiez where they worked on the upper level of the mall near the food court.

Howard County Police Chief Bill McMahon said police used extreme caution during their initial approach to the crime scene because of the heavy amount of ammunition they observed.

They still have not determined a motive for the crime, although McMahon earlier fought down speculation that it stemmed from a domestic dispute.

"This has been reported by some as a domestic-related incident. We have no knowledge of that," McMahon said. "We do not know yet what caused the shooting incident."

Five other people, including one victim who took a gunshot to the foot, were treated at Howard County General Hospital. The other four either had medical conditions or sustained injuries while trying to flee the scene.

The hospital announced on Twitter at 5:20 p.m. ET that all five people had been released.

The Mall in Colombia, a sprawling shopping center with more than 200 stores, is located in a commuter town with a population of about 100,000 between Washington, DC, and Baltimore, MD, on Interstate 95.

A mall employee, Colin Ready, told CNN he heard the boom and knew it was a gunshot, even though there is construction work at the mall.

McMahon originally refused to give specifics as to where the shooting took place, but police later said on Twitter that the shooting happened at a skate shop called Zumiez on the mall's upper level.

"To our knowledge, all the activity took place at one time in one store," McMahon said.

Judy Hoffman, manager at Fire and Ice, told CNN she found out there was a shooting from asking people she saw running past to escape the scene.

She said she alerted customers and moved everyone to the back room and turned off the lights. She told CNN that the mall eventually notified them of the situation, but it was half an hour later.

Police said the first call to 911 came in around 11:15 a.m. ET time. Police confirmed the deaths at 12:19 p.m.

Police were on the scene within two minutes, according to Howard County Executive Ken Ulman. He attributed the quick response time to previous training law enforcement had with mall staff.

The mall had been placed on lockdown while SWAT teams cleared people out, and officials closed it for the rest of the day.

This is the first shooting at a mall since a gunman opened fired in a New Jersey mall in early November 2013. He was later found dead from a self-inflicted gunshot wound.

Previously, on Dec. 11, 2012, two people were killed and one was injured when Jacob Roberts, 22, opened fire at the Clackamas Tower Center near Portland, OR. Roberts also killed himself in that incident.